Yukiko Yamaguchi
Yukiko Yamaguchi (Japanese: 山口雪子, Yamaguchi Yukiko) is a dual-nationality Japanese/American, born in Japan in 2015. Her parents were Japanese nationals from Yamaguchi City, Yamaguchi Prefecture, Japan, who removed to Susanville, California after being hired by the Wolff-Von Barronov Corporation (WVBCorp) in 2020. They were both theoretical physicists, who went to work at the company's Institute of Singularity Studies. Yukiko was their only child, at least through 2150.
Yukiko Yamaguchi first appears in, and is the protagonist in, the Timelines Universe novel The Cross-Time Kamaitachi.
Early Life
Yukiko was brought up in a very traditional Japanese household by very traditional Japanese parents. Japanese was spoken in the home on alternate days with English (though Japanese was spoken four days a week versus English on only three days, because her parents understood she would get plenty of English speaking done in school). She also spent summers and the longer holidays in Japan with family there.
Yukiko was a friendly sort who got along with everyone, including "the bad girls and the good girls in high school". She graduated near the top of her class and went on to engineering school at Stanford University, where she earned a bachelor's in Electrical Engineering and a Master's in Electronics Technology. Her D.Eng. in Electronics Engineering with a specialty in Control Systems was granted by Purdue University. She had attended both colleges via grants from WVBCorp, who hired her directly out of school to work on advanced control systems for the Heinlein-Alcubierre singularity space drive.
Work for WVBCorp
She followed in her parents' footsteps at WVBCorp's Institute of Singularity Studies, working on what the company considered critical development projects centered around the drive, but she also had a hand in other projects, including but not limited to singularity power generation and an early look at the failed South Chinese interstellar portal system.
Disappearance
On 25 June 2050, Yukiko disappeared from her high-security laboratory in Susanville, leaving her interns and co-workers scratching their heads as to how she could possibly have gotten past them through the lab's single security door:
"Apparently she was at work one day in her lab, doing something with an experimental control system for the singularity drive, and walked around behind the equipment to check on something. According to eyewitnesses who were in the room at the time, she never came back. And there was no way to exit the room from that position; it was a secure lab, one entrance, cameras on both sides of the door, card swipe, retinal scan, and nano ping required for both entry and exit."
It was later discovered she had fallen through a rift in space-time caused by a "leaky" electronic fitting attached to her test apparatus, which contained among other things a tiny nano-singularity. She landed on a hilltop near the Aratani Dam in Yamaguchi Prefecture, Japan, in Timeline 1287 left sub 6 -- or in other words, a very, very long way from home in Timeline Zero.
Search
After determining what had happened in the lab, the principal officers of WVBCorp, John Wolff and Christopher von Barronov, ordered a search to be made for Yukiko throughout the timelines, both left and right, including all sub and supra lines related to them. This search would turn out to last a hundred years. They didn't care; as Marines, they held to the doctrine of "no one left behind." In the end, it turned out she had been located by a drone nearly seventy-five years before she was found; the drone that located her had been mislaid and its data not analyzed until 2150, when a new push to re-analyze data started on the hundredth anniversary of her loss. No blame was attached to any person or persons for the drone being mislaid; at the time, they were throwing hundreds of expendable drones at the problem, and more than a few either didn't return at all, or were mislaid after returning to the frigate from which they were launched (USSF Constellation, FFS-2). The hundredth anniversary "second look" was initiated after a number of overlooked drones were found in various storage compartments aboard the Constellation during her refit in 2149.
A team was dispatched immediately to Timeline 1287 left sub 6, where it was believed she was in Tokyo -- at least, that was where the drone had picked up a ping from her nanos back in 2076. But when they rotated into the target timeline, new real-time data collection placed Yukiko somewhere near Hiroshima; and that was where the mixed team of Space Force Marines and civilian historians and techs were landed -- in the midst of what was clearly a post-apocalyptic society. By asking around discreetly, avoiding what appeared to be Japanese Imperial troops based on the docks in Miyajimaguchi, they discovered Yukiko (or more to the point, a strange, ageless demon woman who was known to be something of a rōnin samurai) was living on Mount Misen, on Itsukushima Island across the strait from Hiroshima, and they were directed to ask for her at the Daishōin Temple in Miyajima City. The monastery's leader, Abbot Masanori, directed them up the mountain on a pilgrims' trail to another temple complex near the summit of Mount Misen; and it is here that the novel The Cross-Time Kamaitachi opens.
Swords
On her second day in the new timeline, Yukiko foraged for gear in a small neighborhood in Kamitengamachi, near the temple where she'd discovered Taro and Aoi. In one house, she discovered a good-sized collection of ancient weapons, including two beautiful, matched katana. The papers of attestation or provenance of the two swords and their matching saya indicated they had been made for the first "real" shōgun, Minamoto no Yoritomo, or possibly one of his top lieutenants, at the end of the Heian era or beginning of the Kamakura era -- in other words, nearly a thousand years before. The papers recounted a legend that the swords were somehow haunted or possessed, giving their wielder supernatural powers when they were sufficiently "awakened". Yukiko experiences this power at least five times in The Cross-Time Kamaitachi:
- The skirmish at Nirō Station
- The Battle of the Hanna Gate
- The Tōdai-ji, when she kills the monk Sadao
- The Battle of Fuji, on the way to Tokyo
- The Battle of The Three Palace Sanctuaries, in Tokyo
At the Tōdai-ji, she starts screaming about the swords being thirsty:
As she ran, she kept kicking bones and other things out of her way. She realized at length the bones were from nihonjiki. And that infuriated her even more. "KILLER OF INNOCENT DEER!" she bellowed. "MY SWORDS THIRST FOR REVENGE! SHOW YOURSELF THAT I MAY SLAKE THEIR BLADES IN YOUR BLOOD!"
Yoshiaki looked at Hiroyuki. "Is this . . . normal, in your recollection?"
"Um . . . not exactly," said his cousin, brow furrowing. "I do remember her shouting something about her blades being thirsty, but just once, at the Hanna Gate, and then she calmed down after the killing stopped."
"Do you suppose the katana are . . . "
"Haunted? How old are they supposed to be?"
"She said possibly they belonged to Minamoto no Yoritomo." Yoshiaki shrugged.
Hiroyuki paled. "The first shōgun? That old?"
"So she said."
"There are rumors about a pair of matched swords . . . "
"Yes," said Yoshiaki. "I know. And I kept my mouth shut. Now kindly keep yours shut and let's follow her before she gets out of sight and goes completely nuts." They took off at a dead run, following Yukiko as she danced and whirled off to the east end of the temple.
And a moment later, she comes to a realization about the swords, and herself:
"It doesn't matter," she whispered to herself, as she swung and swung and swung. "The blades thirst for their blood. I thirst for vengeance. I was made for this work and so were they."
Mostly what she notices is that time slows down for the rest of the world (she speeds up as far as the rest of the world is concerned) and the swords make it clear to her that they are thirsty and wish to be used to kill. It is possible what is really embedded in the swords is some sort of link to the Mesh, similar to what Ariela Rivers Wolff and Delaney Wolff Fox have that allows them also to move supernaturally fast when danger is imminent.
When she fights in single combat, the swords do not appear to be awakened, or do not wake in time, or perhaps the power arises only when the wielder is fighting multiple enemies at once. This suggests that the Mesh power (if that's what it is) is embedded in the swords and is not possessed directly by Yukiko (or any other former wielder).